U.S. patent number 5,047,857 [Application Number 07/340,832] was granted by the patent office on 1991-09-10 for television system with zoom capability for at least one inset picture.
This patent grant is currently assigned to Thomson Consumer Electronics, Inc.. Invention is credited to David J. Duffield, David L. McNeely.
United States Patent |
5,047,857 |
Duffield , et al. |
September 10, 1991 |
Television system with zoom capability for at least one inset
picture
Abstract
A television system including a memory for storing subsampled
fields in different sectors corresponding to respective small
pictures of a rectangular multi-picture array, includes apparatus
for expanding the subsampled fields, preferably to full-screen
size, as they are read-out of the memory. When the stored
sub-sampled fields correspond to different fields of the same video
signal, the arrangement provides for a re-animated version of
multi-picture array in a so-called "instant replay" mode of
operation.
Inventors: |
Duffield; David J.
(Indianapolis, IN), McNeely; David L. (Indianapolis,
IN) |
Assignee: |
Thomson Consumer Electronics,
Inc. (Indianapolis, IN)
|
Family
ID: |
23335113 |
Appl.
No.: |
07/340,832 |
Filed: |
April 20, 1989 |
Current U.S.
Class: |
348/553;
348/E5.112; 348/561; 348/578 |
Current CPC
Class: |
H04N
5/4448 (20130101); H04N 5/45 (20130101) |
Current International
Class: |
H04N
5/44 (20060101); H04N 5/45 (20060101); H04N
005/262 () |
Field of
Search: |
;358/183,22,180,182,903,181 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0013124 |
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Jul 1980 |
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EP |
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0122094 |
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Oct 1984 |
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EP |
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51172 |
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May 1981 |
|
JP |
|
2047041 |
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Nov 1980 |
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GB |
|
2189106 |
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Oct 1987 |
|
GB |
|
2222742 |
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Mar 1990 |
|
GB |
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Other References
A Recent Innovation in Digital Special Effects--The CBS "Action
Track" System, by J. Moore et al., SMPTE Journal, vol. 87, No. 10,
Oct. 1978, pp. 673-676. .
Digital Video Effects, by Masao Inaba, et al., NEC Research &
Development No. 56, Jan. 1980, pp. 130-134. .
User's Manual for the Toshiba 30ID1 Television Receiver, pp. 23-28
(translation attached). .
"Service Manual KV-27TX20 RM-754 P-3A Chassis" copyright, SONY,
1988.4, pp. 2-8 and 22-27..
|
Primary Examiner: Chin; Tommy P.
Attorney, Agent or Firm: Tripoli; Joseph S. Emanuel; Peter
M.
Claims
What is claimed is:
1. A method of operating a television system to provide an
"instant-replay" feature, comprising the steps of:
compressing successive fields of a television signal;
storing successive ones of said compressed fields in respective
sectors of a memory device;
retrieving ones of said stored compressed fields from said memory
sectors in a repetitive sequence; and
expanding ones of said retrieved compressed fields in said
repetitive sequence to produce a sequence of television fields.
2. The method recited in claim 1, further including the steps
of:
maintaining the contents of said memory device unchanged after all
of said memory sectors contain respective ones of said compressed
fields.
3. The method recited in claim 1, wherein:
said compressing step includes subsampling pixels and lines of said
fields; and
said expanding step includes the step of interpolating said pixels
and lines of said compressed fields stored in said memory
sectors.
4. The method recited in claim 3, wherein:
said interpolating step includes the step of repeating at least one
of the lines and pixels of said compressed fields.
5. The method recited in claim 1, wherein:
said compressed fields are stored in a field memory.
6. The method recited in claim 1, further including the step
of:
changing the order of retrieving said ones of said stored
compressed fields.
7. The method recited in claim 1, further including the step
of:
changing the rate of sequencing through said repetitive
sequence.
8. A method of operating a picture-in-picture television system to
provide an "instant-replay" feature, comprising the steps of:
subsampling successive fields of a television signal;
storing successive ones of said subsampled fields in respective
sectors of a memory device; and
retrieving and expanding said ones of said subsampled fields stored
in said memory sectors in a repetitive sequence to produce a
sequence of television fields.
9. The method recited in claim 8, further including the steps
of:
maintaining the contents of said memory device unchanged after all
of said memory sectors contain respective ones of said compressed
fields.
10. The method recited in claim 8, wherein:
said expanding step includes the step of interpolating lines and
pixels of said compressed fields.
11. The method recited in claim 10, wherein:
said interpolating step includes the step of repeating at least one
of the lines and pixels of said compressed fields.
12. The method recited in claim 8, wherein:
said compressed fields are stored in a field memory.
13. The method recited in claim 8, further including the step
of:
changing the order of retrieving said ones of said stored
subsampled fields.
14. The method recited in claim 8, further including the step
of:
changing the rate of sequencing through said repetitive
sequence.
15. A television system with an "instant-replay" feature,
comprising:
means for compressing successive input fields of a television
signal to produce successive compressed fields having fewer lines
and pixels than respective ones of said input fields;
means for storing successive ones of said compressed fields in a
predetermined number of respective memory sectors; and
means for retrieving and expanding said compressed fields stored in
said respective memory sectors in a repetitive sequence to produce
a sequence of television fields.
16. The system recited in claim 15, wherein:
said means for storing maintains the contents of all of said
predetermined number of said respective memory sectors unchanged
after all of said predetermined number of said respective memory
sectors contain said successive ones of said compressed fields.
17. The system recited in claim 15, wherein:
said means for compressing includes means for deleting lines and
pixels of said input fields; and
said means for expanding includes means for interpolating lines and
pixels of said compressed fields.
18. The system recited in claim 15, wherein:
said means for storing has a capacity corresponding to one of said
input fields.
19. The system recited in claim 15, wherein:
said means for retrieving and expanding includes means for changing
the order of retrieving said stored compressed fields.
20. The system recited in claim 15, wherein:
said means for retrieving and expanding includes means for changing
the rate of sequencing through said repetitive sequence.
21. In a picture-in-picture television system including a memory
for storing compressed versions of respective input fields of a
television signal in respective memory sectors, the compressed
fields stored in said respective memory sectors corresponding to
respective picture sectors of a multiple picture display produced
during a "multiple-picture" mode of operation, apparatus
comprising:
means for reading and expanding the contents of said respective
memory sectors in a repetitive sequence to produce a sequence of
expanded television fields corresponding to respective pictures
larger in size than said respective picture sectors during an
"instant replay" mode of operation.
22. The method recited in claim 21, wherein:
said means for reading and expanding includes means for changing
the order of reading said contents of said respective memory
sectors.
23. The method recited in claim 21, wherein:
said means for reading and expanding includes means for changing
the rate of sequencing through said repetitive sequence.
24. A television system with an "instant-replay" feature,
comprising:
means for compressing successive fields of a television signal;
means for storing successive ones of said compressed fields in
respective sectors of a memory device;
means for retrieving and expanding ones of said stored compressed
fields in a repetitive sequence to produce a sequence of television
fields; and
control means coupled to said means for retrieving and expanding
for changing the rate of sequencing through said repetitive
sequence.
25. A television system with an "instant-replay" feature,
comprising:
means for compressing successive fields of a television signal;
means for storing successive ones of said compressed fields in
respective sectors of a memory device;
means for retrieving ones of said stored compressed fields from
said respective sectors of said memory device in a repetitive
sequence;
control means coupled to said means for retrieving for changing the
order in which said ones of said stored compressed fields are
retrieved in said repetitive sequence; and
means for expanding said retrieved ones of said stored compressed
fields in said repetitive sequence to produce a sequence of
television fields.
Description
FIELD OF THE INVENTION
The present invention generally concerns the field of television
systems with "picture-in-picture" and/or "multiple-picture"
provisions.
BACKGROUND OF THE INVENTION
A number of commercially available television sets and video
cassette recorders have picture-in-picture (also called
"pix-in-pix" or simply P-I-P) and multi-picture (also called
"multi-pix") provisions.
In one form of the multiple-picture feature, essentially multiple
"still" pictures derived from the same video source (e.g., channel)
"taken" at successively different times are simultaneously
displayed in a rectangular array and thereafter periodically and
sequentially up-dated. This provides a type of static stroboscopic
display which, may be used to study the progression of an action
such as swinging a golf swing.
SUMMARY OF THE INVENTION
With regard to one aspect of the present invention, it has been
recognized by the present inventors that it is desirable to
sequentially magnify (or "zoom") individual ones of the plurality
of the small inset pictures of a multi-picture array to a larger,
e.g., full screen, size in order to "re-animate" the action in what
may be termed an "instant replay" mode.
Specifically, with regard to the disclosed embodiment, another
aspect of the invention concerns the structure for magnifying at
least one picture insert, particularly the context of a
multi-picture memory arrangement. More specifically, this structure
comprises, in cascade, subsampling unit which produces one sample
for a given number, N, of input video samples, a memory for storing
the subsamples, and an interpolator for producing interpolated
samples from the stored subsamples. The memory is operated so that
the subsamples are written-in at one rate and read-out at a
different rate to affect a picture size change.
To produce the "instant replay" operation referred to above, the
memory is loaded in a plurality of memory sectors with respective
subsampled fields of a video signal. In sequence, each sector of
the memory is read out at a rate slower than the write-in rate and
the stored subsamples are interpolated to produce interpolated
samples. The read-out subsamples and the interpolated subsamples
are combined to produce resultant output video samples which are
coupled to a display device. The displayed picture comprises a
sequence of enlarged images, each image corresponding to a smaller
image associated with a respective section of the memory.
BRIEF DESCRIPTION OF THE INVENTION
The invention will be described with reference to the accompanying
drawing in which:
FIG. 1 is a block diagram of a picture-in-picture processor
including a preferred embodiment of the present invention;
FIGS. 2a and 2b represent displayed images useful in understanding
various operating modes of the processor shown in FIG. 1; and
FIGS. 3a and 3b represent memory arrangements useful in
understanding various operating modes of the processor shown in
FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
The picture-in-picture processor shown in FIG. 1 may be
incorporated, e.g., in a television system which includes a display
device such as a television set or monitor or in a television
system which does not include a display device such as a video
cassette recorder/player (VCR). In the former case, the output
signal of the picture-in-picture system is coupled to the driver
for display unit, e.g., a kinescope. In the latter case, the output
signal of the system is intended to be coupled to a television
system which includes a display device such as a television set,
either as a baseband video signal or as a modulated RF carrier,
through an output signal connector.
The various operations are performed in component form and one
processor like the one shown in FIG. 1 is utilized for each
component. The components may be luminance (Y) and two color
difference signals (e.g., R-Y and B-Y or I and Q) or three color
difference signals. The following description is made with respect
to the luminance (Y) component, but applies similarly to the color
difference signals; noting however, that lower sampling and clock
frequencies are utilized and that less memory capability is
required.
The picture-in-picture processor shown in FIG. 1 includes a first
video signal source 10, e.g., comprising the tuner/demodulator
section of television system in which it is incorporated, and a
second video signal source 12, e.g., comprising a baseband video
input signal connector.
The baseband video signals produced by sources 10 and 12 are
coupled to a first switching unit 14. First switching unit 14 as
well as other portions of the picture-in-picture, processor are
controlled by a microprocessor (.mu.P) control unit 16.
Microprocessor control circuit 16 generates control signals for the
picture-in-picture processor in accordance with a stored set of
instructions, i.e., a computer program and in response to commands
received from a user command entry unit 18, typically including a
keyboard (not shown).
The picture-in-picture processor has several operating modes
selectable in response to user entered commands. In part, these
operating modes are established by the switching states of first
switching unit 14, a second switching unit 20, a third switching
unit 22, and a fourth switching unit 24.
First switching unit 14 has a first input IN1 and a second input
IN2, to which the first and second video input signals are
respectively coupled, two outputs OUT1 and OUT2, and, under the
control of microprocessor control circuit 16, is capable of
providing the following connection configurations.
______________________________________ OUT 1 OUT 2
______________________________________ IN1 IN1 IN2 IN1 IN1 IN2 IN2
IN2 ______________________________________
Output OUT2 of first switching unit 14 is coupled to the cascade
arrangement of an analog-to-digital converter (ADC) 26, a
subsampling unit 28 and a first input IN1 of second switching unit
20. Second switching unit 20, has a second input IN2, to which the
output of ADC 26 is coupled, and an output OUT. Second switching
unit 20 has a single pole, double throw operation and accordingly
connects either of inputs IN1 and IN2 to output OUT as is indicated
by the switching symbol within the block.
Output OUT of second switching unit 20 is coupled to the cascade
arrangement of a memory 30, an interpolator unit 32 and a first
input IN1 of third switching unit 22. Third switching unit 22 has a
second input IN2, to which the output memory 30 is coupled, and,
like second switching unit 20, has a single pole, double throw
operation.
Output OUT of third switching unit 22 is coupled to the cascade
arrangement of a digital to analog converter (DAC) 34 and a first
input IN1 of fourth switching unit 24. Fourth switching unit 24 has
a second input IN2, to which first output OUT1 of first switching
unit 14 is coupled, and also has a single pole, double throw
operation. The output signal of the picture-in-picture processor is
developed at output OUT of fourth switching unit 24.
A clock generator 36 generates clocking and timing signals for
various portions of the picture-in-picture processor.
A write/read control unit 38, under the control of microprocessor
control unit 16, generates address signals and write and read
clocking signals for memory 30. Write/read control unit 38 receives
pairs of horizontal (H) and vertical (V) synchronization signals
from both video sources for synchronizing the write and read
operations of memory 30 in the various operating modes.
With the arrangement shown in FIG. 1, several primary modes of
operation are possible. These are:
1. normal=full screen display from either video source;
2. zoom=magnified display from either video source;
3. picture-in-picture=small picture from either video source inset
within full-screen display from other video source;
4. multi-picture=display of plurality of small "still" images in
rectangular array (the "still" images are periodically and
sequentially updated); and
5. "instant replay" - sequential and repetitive enlargement (e.g.,
full screen) of small "still" images to form a re-animated form of
a corresponding multi-picture array.
These modes of operation correspond to different configurations
produced by controlling the various switching units and other
components and will be explained in detail below. The following
table briefly relates the operating modes with the
configurations.
______________________________________ MODE ACTIVE UNITS SWITCH
STATUS ______________________________________ 1. NORMAL selected
video SW1 selects source directly source (IN1 or connected to IN2);
SW4 output selects IN2 2. ZOOM ADC26; SW1 selects memory 30;
source; SW2 interpolator 32; selects IN2 DAC34 to by-pass
subsampler 28; SW3 selects IN1; SW4 selects IN1 3. PICTURE-IN-
ADC26; SW1 selects PICTURE subsampler 28; main and inset memory 30
(IN1 or IN2); (stores every SW2 selects subsampled IN1; SW3 field
in one selects IN2 sector), DAC34 to by-pass interpolator 32; SW4
switches between IN1 and IN2 4. MULTI-PICTURE ADC26; SW1 selects
subsampler 28; source; SW2 memory 30 stores selects IN1; successive
SW3 selects subsampled IN2 to by-pass fields in interpolator
respective 32; SW4 sectors; DAC34 selects IN1 5. INSTANT ADC26; SW1
selects REPLAY subsampler 28; source; SW2 memory 30 stores selects
IN1 successive (subsampler subsampled 28 not fields in by-passed)
successive SW3 selects sectors as in IN1 pix-in-pix; (interpolator
interpolator 32; 32 not by- DAC34 passed); SW4 selects IN1
______________________________________
Now modes 2, 3, 4 and 5 will be described in detail. The mode 1
(normal) is believed to be sufficiently clear from the above table.
It is only noted that since the normal mode only involves the
selection of a video source and does not involve any digital
operations, the conversions to and from digital form are not
necessary.
ZOOM MODE
The purpose of the zoom mode of operation is to magnify or "blow
up" the entire image produced from the selected video signal. Of
course, because the display device has a fixed display area (i.e.,
scanning area), those portions of the magnified image falling
outside the display area (due to the magnification will not be
visible. Thus, only a portion of the image is effectively
magnified. In other words, the viewer perceives a "zooming-in" on a
portion of the original image.
ADC 26 is used in all the modes except the normal mode.
ADC 26 converts the selected analog video signal coupled to it by
first switching unit 14 to digital video samples occuring at the
sampling rate determined by clock generator 36. The sampling
frequency or rate for the luminance component can be a multiple of
the color subcarrier frequency (fsc), for example 3 fsc, or a
mulitple of the horizontal scanning frequency. The digital video
samples produced by ADC 26 are coupled to subsampler unit 28 and to
second input IN2 of second switching unit 20.
Subsampler unit 28 is utilized in the picture-in-picture,
multi-picture and instant replay modes of operation. However in the
zoom mode of operation, second switching unit 20 is caused to
connect second input IN2 to output OUT, thereby by-passing
subsampler unit 28 and directly coupling the output of ADC 26 to
the input of memory 30.
Memory 30 is utilized in all but the normal mode of operation.
Memory 30 is capable of storing samples for an entire field of
complete (not subsampled) video information, e.g., for luminance,
512 samples (or pixels) per line and 256 lines.
In the zoom mode of operation, as noted above, subsampler unit 28
is by-passed by second switching unit 20, and therefore memory 30
stores an entire field of complete (not subsampled) video
information. The 512 samples of each line and 256 lines of each
field are sequentially written into memory 30 sample-by-sample,
e.g., left to right, and line-by-line, e.g., top to bottom, at the
sampling rate (3f.sub.sc) of ADC 26 and sequentially read out in
the same order, but at a slower rate. The relatively slower reading
rate causes the samples and lines to be separated further apart in
time and therefore to appear correspondingly separated further
apart in space in a displayed image. The reading rate is
controllable by microprocessor control unit 16 to control the
amount of magnification.
In the zoom mode, output of memory 30 is coupled to interpolator
unit 32. Interpolator unit 32 is not used in the picture-in-picture
and multi-picture modes, it being by-passed by third switching unit
22 in those modes.
Interpolator unit 32 in concert with WRITE/READ memory control unit
38 provides missing interstitial samples and lines.
Interpolator unit 32 sequentially provides the "real" and
"interpolated" samples in interleaved form to third switching unit
22 and thereby to DAC 34. The analog signal produced by DAC 34 is
coupled through fourth switch 24 to the output of the
picture-in-picture processor. DAC 34, like ADC 26 (and memory 30),
is used in all but the normal mode, since the picture-in-picture
processor operates in digital form in all but the normal mode.
Other possible zoom features are discussed in copending patent
application Ser. No. 340,931, entitled "Apparatus And A Method For
Automatically Centering A Video Zoom and Pan Display", concurrently
filed with this application on Apr. 20, 1989 in the names of B. A.
Canfield, D. J. Duffield and D. L. McNeely.
PICTURE-IN-PICTURE MODE
The purpose of the picture-in-picture mode is to insert a small or
inset picture corresponding to one of the two input video signals
within the full screen picture corresponding to other input video
signal (see FIG. 2a). Either video signal can be chosen to produce
the inset picture and the two can be "swapped" under user
control.
In the picture-in-picture mode of operation, subsampler unit 28 is
not by-passed by second switching unit 20.
Subsampler unit 28 reduces the number of video samples received by
it during each horizontal scan line by a factor N and also reduces
the number of scan lines per field by a factor N. Thus, one output
sample is produced for every N input samples and one scan line is
produced for every N scan lines. The factor N is controlled by
microprocessor control unit 16 to determine the size (length and
height) of the small picture inset in the picture-in-picture mode
(and also determines the size and therefore number of picture
insets in the multi-picture mode.)
Subsampler unit 28 may, for example, comprise a sample averaging
arrangement for averaging N samples followed by a line averaging
arrangement for averaging N lines.
The subsampled fields of video information corresponding to the
small or inset picture are written into a predetermined area of
memory 30 controlled by microprocessor control unit 16. Since a
subsampled field contains fewer samples and lines (determined by N)
than a complete field, only a portion of memory 30 is occupied by
the samples of the subsampled field and the rest of memory 30 may
be considered as being empty.
For example, with reference to FIG. 3a in the present embodiment,
writing of the subsampled field begins at the "top-left" memory
location (indicated by the dot), corresponding to line 1, sample 1
of the complete field and ends at some memory location (indicated
by the X) dependent on N, thus "filling-in" only the top-left
sector. The circle represents the memory location at which reading
begins. By changing the address of the memory location at which
reading begins, horizontal and vertical time delays are introduced
before the inset field information is read out. These delays
correspond to horizontal and vertical spatial shifts of the inset
picture in the displayed image.
In the picture-in-picture mode, the write-in rate is slower than
the read-out rate (related to the subsampling factor N), the size
reduction for the inset picture being produced as a result of
subsampling.
As earlier noted, in the picture-in-picture mode, third switching
unit 22 is controlled by microprocessor control unit 16 to connect
second input IN2 to output OUT, thereby by-passing interpolator
unit 32 and directly coupling the output of memory 30 to DAC 34.
Thus, interpolator unit 32 is not available for controlling the
size of the inset picture in the present embodiment, that function
being accomplished by controlling the sub-sampling factor N of
subsampler 28.
The analog output signal of DAC 34 and the unconverted analog
signal produced at first output OUT1 of first switching unit 14 are
coupled to first input IN1 and second input IN2, respectively, of
fourth switching unit 24. Fourth switching unit 24, under the
control of microprocessor control unit 16, replaces the main video
signal with the inset video signal (produced at the output of DAC
34) in the appropriate time interval corresponding to the desired
location of the inset picture within the main picture. In this
regard, the operation of fourth switching unit 24 is synchronized
with the read operation of memory 30.
Other features concerning the positioning and sizing of the inset
picture are described in copending patent application Ser. No.
341,123 entitled "INSET PICTURE CENTERING IN A PIX-IN-PIX SYSTEM"
concurrently filed with the present application on Apr. 20, 1989 in
the names of B. A. Canfield and D. J. Duffield.
MULTI-PICTURE MODE
The purpose of the multi-picture mode is to display a rectangular
array of small picture insets. The small pictures may correspond to
different fields of the same video signal or different fields of
different video signals, such as may be provided at different
channels.
As in the picture-in-picture mode of operation, the subsamples
provided by subsampler 28 are written-into and read-out of memory
30 at different rates, the write-in rate being slower than the
read-out rate. However, unlike in the picture-in-picture mode of
operation, the subsamples from successive fields are not written
into the same area of memory, but rather, into different respective
areas or sectors, such as shown in FIG. 3b, under the control of
microprocessor control unit 16. In addition to controlling the
storage location of the different fields within memory 30,
microprocessor control unit 16 also determines the rate at which
subsampled fields are written into respective memory sectors. The
number of small pictures in the rectangular array is related to the
size of the pictures and therefore subsampling factor N.
If the field sampling rate is relatively slow, the small pictures
will appear as still images. In the case different fields of the
same video signal are sampled at a slow rate, the small pictures
will appear as stroboscopic "snap-shots" of an event taken at
different times (see FIG. 2b) and as such, may be useful to study
the various states of the event in detail.
When the fields are to be derived from different video sources such
as different television channels, microprocessor control unit 16
has the additional function of coordinating the channel changes and
is therefore coupled to the channel selection control input of the
tuner of the appropriate video source, as is shown in FIG. 1.
The stored subsampled fields are repetitively read-out of the
respective sectors of memory 30 coupled to DAC 34 through third
switching unit 22. As in the case of the picture-in-picture mode,
interpolator unit 32 is by-passed. In the multi-picture mode,
unlike in the picture-in-picture mode, fourth switching unit 24
continuously couples the output of the DAC 34 to the output of the
picture-in-picture processor.
INSTANT REPLAY MODE
The capability of the picture-in-picture processor to couple
subsampler unit 28, memory 30 and interpolator unit 32 in cascade
allows for a so-called "instant replay" mode of operation
previously referred to as well as an artistic "mosaic" mode of
operation not previously referred to.
The "instant replay" mode of operation has in common with the
multi-picture operation the manner in which different fields are
stored in respective sectors of memory 30 (see FIG. 3b). However,
unlike in the multi-picture mode: (1) the read-out rate is the same
as the write-in rate; and (2) interpolator unit 32 is not by-passed
but is instead coupled between the output of memory 30 and the
input of DAC 34 by means of third switching unit 22.
In addition, in the "instant replay" mode, the write operation is
stopped after each sector has been loaded, and thereafter the
sectors are sequentially and repetitively read out. The rate at
which the sectors are addressed to be read out is user controllable
to provide a range between slow motion reproduction and rapid
motion reproduction. Further, the sequence can be changed, e.g.,
reversed under user control. The rate at which the samples and
lines are read out of an addressed sector determines the
expansion.
The result of this is that, as the subsampled fields are
sequentially read out the respective sectors of memory 30 they are
enlarged so that a sequence of enlarged, preferably near full
screen size, "snap-shots" is repetitively displayed. This changes
the previously essentially still multi-picture display and provides
an animated, continuous loop stroboscopic study vehicle of the
event previously stored.
The same type of operation can be provided when the fields stored
in the sectors of memory 30 correspond to different channels.
MOSAIC MODE
The selectable configuration of subsampler unit 28, memory 30 and
interpolator unit 32 also provides for a mosaic mode of operation
whereby a full screen picture is produced in which image areas
several pixels high and long have the one color. In this mode, the
configuration is the same as in the zoom mode except that
subsampler unit 28 is not by-passed but instead, coupled between
the output of ADC 26 and input of memory 30. As a result,
subsampled fields of the input video signal will be expanded, with
each sample and line of the subsampled field repeated (by
interpolator unit 32).
* * * * *